Conventional sodar systems employ directed sound waves to detect atmospheric phenomena such as wind speed. By directing sound beams into the atmosphere in a number of directions and measuring the Doppler shift of echoes returned from turbulence and thermal variations in the atmosphere, wind speed and other atmospheric phenomena can be accurately estimated.
The predominant type of sodar system in current use is the monostatic phased array sodar system. Monostatic sodar emanates sound beams and detect sound beam reflections from a single location. Phased array monostatic sodars direct the beams in different directions, and are sensitive to echoes returned from these directions, by use of an array of sound transducers. These transducers are configured to transmit and receive in groups of differing phase so as to direct the transmitted sound beams and regions of sensitivity, as desired.